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ABD launches new axle parameter measurement system
ABD launches new axle parameter measurement systemKeyword: Measurement
Anthony Best Dynamics (ABD) of Wiltshire in England has extended the company's range of suspension testing systems with the launch of the new Axle Parameter Measurement Machine (APMM). A derivative of the successful Suspension Parameter Measurement Machine (SPMM), the APMM offers a lower cost alternative, by testing only one axle of a vehicle at a time, whilst providing much of the data that can be measured by the SPMM (see Plate 3).
Though it has been designed to enable fully assembled vehicles to be tested, the APMM is equally suited to the measurement of axle units mounted on test frames and so is ideal for companies developing axle or corner suspension units for supply to major vehicle manufacturers.
Plate 3 Anthony Best Dynamics (ABD) of Wiltshire in England has extended the company's range of suspension testing systems with the launch of the new axle parameter measurement machine
The APMM utilises the same accurate and reliable control and measurement technology used in the well-proven SPMM, but features a simpler mechanical configuration to minimise costs. Electro-mechanically operated, fully automated and computer controlled, the APMM machine still provides a fast method for obtaining suspension and steering measurements of vehicles.
The new APMM takes measurements by applying vertical or horizontal inputs to the suspension of a vehicle. It does this by moving the platens positioned beneath the wheels, whilst keeping the body of the vehicle stationary. This differs from the SPMM, which applies horizontal inputs to the suspension by movement of the wheel platforms, but generates roll, pitch and vertical inputs by moving the body of the vehicle.
The APMM is capable of applying longitudinal, lateral, vertical and aligning torque inputs independently to each wheel of the axle unit. Kinematics measurements are made by moving the wheel platforms vertically, in-phase to generate bounce inputs to the suspension and in anti-phase to simulate roll inputs. During kinematics tests, the horizontal axes of the machine are normally controlled to maintain zero load. Compliance tests are generally carried out by applying inputs to the horizontal axes, with the vertical axes held at a fixed position.
Each wheel station contains a multi-axis six-component load cell, which enables all of the forces and movements acting on the wheel to be measured and the centre of pressure of the tyre contact patch to be determined.
As in the SPMM, the wheel position measurement system uses an array of "string" encoders mounted on a stand beside each wheel station. The stainless steel wire "strings" are connected to a fixture, which is then attached to the wheel. The system measures five of the wheel's six degrees of freedom: X, Y, Z, Steer and Camber, while Wheel Castor can also be measured using an inclinometer, which can be supplied as an option.
Each axis of the APMM is driven by a brushless servomotor, using either force or position control. The use of electrical servomotors throughout ensures a long working life with a minimum of maintenance and running costs. The machine also provides quiet and clean working conditions for its operators and is suitable for installation in a laboratory environment.
The APMM is designed to be either floor mounted or installed into a special pit, with bed plates that support the car, mounted at floor level. Adjustable height clamps bolted to the bed plates grip the underside of the vehicle to keep it stationary. If the APMM is floor mounted, it is supplied with two additional frames to which the bed plates are attached.
The APMM has a fast set-up time and an easy "drive on" vehicle installation to allow maximum productivity when testing. The machine also has excellent access underneath the vehicle for suspension modification. Testing can be carried out with standard wheels and tyres or alternatively with wheel substitutes fitted. The APMM is controlled by a computer system with an easy-to-use operator interface running under Windows NT. The software uses a database to store all vehicle, test set up, instrumentation and results information. The software is supplied with a simple-to-use plotting facility, to allow results to be quickly examined in detail at the end of a test and exported in alternative formats for transfer to other systems.
For all sales enquiries contact Tony Best, Anthony Best Dynamics, Holt Road, Bradford on Avon, Wilts BA15 1AJ, UK. Tel: +44 (0)1225 867575.